Analytical Paleobiology

class: center, middle, inverse, title-slide

.title[
# Analytical Paleobiology
]
.subtitle[
## with R
]
.author[
### Gregor H. Mathes
]
.institute[
### University of Bayreuth/ Paleoecology Lectures
]
.date[
### 2021/06/17 (updated: 2022-05-16)
]

---

# Overview 
 
.pull-left[
 
**First ...**

- clean projects
  - R-projects 
  - here functionality  
  
- Tidy data
  - import data
  - tibbles  
]

.pull-right[
 
**and then** 
 
- Tidyverse 
 - wrangle
 - iterate
 - visualize
 
]

---
class:inverse, mline, center, middle
# Tidy project structure

---
# Project structure  
  
.center[![Image of a youtuber (Rachelleea) rethinking what happened in 2019](data:image/png;base64,#https://i.ytimg.com/vi/OjWHL_AYGxc/maxresdefault.jpg)]

.footnote[
[Youtuber Rachelleea](https://www.youtube.com/channel/UCJCgaQzY5z5sA-xwkwibygw)
]
---
# Project structure

.pull-left[
 
**Problem**

- absolute paths
  
- `rm(list = ls())`

- non-reproducible results  
  
- total mess
]

.pull-right[
 
**Solution** 
 
- Rstudio projects

- The `here` package  
  
- disenable workspace preservation
]

---
# What is real?

.center[<img src="data:image/png;base64,#https://d33wubrfki0l68.cloudfront.net/7fa44a5471d40025344176ede4169c5ad3159482/1577f/screenshots/rstudio-workspace.png" alt="Disenable workspace preservation in Rstudio" width="550"/>
]

---
# R projects

.center[![Allison Horsts visualisation of Rstudio projects](data:image/png;base64,#https://pbs.twimg.com/media/EnepKxNVQAAhNhg.jpg)]

---
# R projects

.center[![Start a new project step 1](data:image/png;base64,#https://d33wubrfki0l68.cloudfront.net/87562c4851bf4d0b0c8415dc9d6690493572e362/a6685/screenshots/rstudio-project-1.png)]

---
# R projects

.center[![Start a new project step 2](data:image/png;base64,#https://d33wubrfki0l68.cloudfront.net/0fa791e2621be297cb9c5cac0b2802223e3d7714/57d89/screenshots/rstudio-project-2.png)]  
  
---
# R projects

.center[![Start a new project step 3](data:image/png;base64,#https://d33wubrfki0l68.cloudfront.net/dee6324df1f5c5121d1c1e9eed822ee52c87167b/1f325/screenshots/rstudio-project-3.png)]

---
# Folder structures

.center[![Example project structure](data:image/png;base64,#img/example_project.png)]  
  
---
# Here Package

.center[<img src="data:image/png;base64,#https://raw.githubusercontent.com/allisonhorst/stats-illustrations/master/rstats-artwork/here.png" alt="Allison Horsts visualisation of the here function" width="650"/>
]

---
# The Tidyverse

.center[![The hex symbols for the core tidyverse packages](data:image/png;base64,#http://d33wubrfki0l68.cloudfront.net/2834374971f416c892196363767fd7e1e87e2d1a/288a4/img/tidyverse/tidyverse_all.png)]

---
class: inverse, center

# The Tidyverse

### - collection of easy-to-use tools for data analysis and visualization

### - consistent in both syntax and output

### - widely used in the industry and in science

.center[<img src="data:image/png;base64,#https://peadarcoyle.com/wp-content/uploads/2019/01/hadley-wickham.jpg" alt="Picture of Hadley Wickham" width="500"/>
]

---
background-image: url(data:image/png;base64,#https://raw.githubusercontent.com/tidyverse/tidyverse/master/man/figures/logo.png)
background-position: 90% 10%
## `library(tidyverse)` will load  
## the core tidyverse packages:

#### [ggplot2](http://ggplot2.tidyverse.org), for data visualisation.
#### [dplyr](http://dplyr.tidyverse.org), for data manipulation.
#### [tidyr](http://tidyr.tidyverse.org), for data tidying.
#### [readr](http://readr.tidyverse.org), for data import.
#### [purrr](http://purrr.tidyverse.org), for functional programming.
#### [tibble](http://tibble.tidyverse.org), for tibbles, a modern re-imagining of data frames.
#### [stringr](https://github.com/tidyverse/stringr), for strings.
#### [forcats](https://github.com/hadley/forcats), for factors.

---
# Agenda

## - read in data with the `readr` package
 
## - wrangle data with the `dplyr` package
 
## - visualise data with the `ggplot2` package

---
class:inverse, mline, center, middle
# The *readr* package

---
# readr

Function       | Reads
-------------- | --------------------------
`read_csv()`   | Comma separated values
`read_csv2()`  | Semi-colon separate values
`read_delim()` | General delimited files
`read_fwf()`   | Fixed width files
`read_log()`   | Apache log files
`read_table()` | Space separated files
`read_tsv()`   | Tab delimited values

.center[and many more ...]

---
# readr

```r
dfr <- read_csv("file_name.csv")
```

--
<html>
 <div style='float:left'></div>
 <hr color='#EB811B' size=1px width=720px>
</html>

```r
dfr <- read_csv(here("figures/file_name.csv"))
```
 
--
<html>
 <div style='float:left'></div>
 <hr color='#EB811B' size=1px width=720px>
</html>

```r
url <- 'https://paleobiodb.org/data1.2/occs/list.txt?base_name=Carnivora&show=full'
dfr <- read_csv(file = url)
```

---
# readr

```r
carnivores <- read_csv(file = here("2021_06_18/carnivores.csv"))
```

```
## Rows: 12168 Columns: 118
## ── Column specification ────────────────────────────────────────────────────────
## Delimiter: ","
## chr (84): record_type, identified_name, identified_rank, difference, accepte...
## dbl (15): occurrence_no, reid_no, collection_no, identified_no, accepted_no,...
## lgl (19): flags, accepted_attr, plant_organ, plant_organ2, collection_subset...
## 
## ℹ Use `spec()` to retrieve the full column specification for this data.
## ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.
```

```r
carnivores
```

```
## # A tibble: 12,168 × 118
## occurrence_no record_type reid_no flags collection_no identified_name 
## <dbl> <chr> <dbl> <lgl> <dbl> <chr> 
## 1 117266 occ NA NA 9070 Cynodictis lacustris 
## 2 137493 occ NA NA 11601 n. gen. Enaliarctos n.…
## 3 137495 occ NA NA 11601 Pinnarctidion bishopi 
## 4 138737 occ NA NA 11798 Indarctos sinensis 
## 5 138738 occ NA NA 11798 Protursus sp. 
## 6 138739 occ NA NA 11798 Ursinae indet. 
## 7 138740 occ NA NA 11798 Proputorius lufengensis
## 8 138741 occ NA NA 11798 Sivaonyx bathygnathus 
## 9 138742 occ NA NA 11798 Lutra sp. 
## 10 138743 occ NA NA 11798 Ictitherium gaudryi 
## # … with 12,158 more rows, and 112 more variables: identified_rank <chr>,
## # identified_no <dbl>, difference <chr>, accepted_name <chr>,
## # accepted_attr <lgl>, accepted_rank <chr>, accepted_no <dbl>,
## # early_interval <chr>, late_interval <chr>, max_ma <dbl>, min_ma <dbl>,
## # ref_author <chr>, ref_pubyr <dbl>, reference_no <dbl>, phylum <chr>,
## # class <chr>, order <chr>, family <chr>, genus <chr>, plant_organ <lgl>,
## # plant_organ2 <lgl>, abund_value <dbl>, abund_unit <chr>, lng <dbl>, …
```

---
# Tibbles

## data.frames are the basic form of rectangular data in R (columns of variables, rows of observations)

---
# Tibbles

## data.frames are the basic form of rectangular data in R (columns of variables, rows of observations

## `read_csv()` reads the data into a tibble, a modern version of the data frame

---
# Tibbles

## data.frames are the basic form of rectangular data in R (columns of variables, rows of observations

## read_csv() reads the data into a tibble, a modern version of the data frame.

## a tibble is a data frame

---
# Saving data

Function            | Writes
------------------- | ----------------------------------------
`write_csv()`       | Comma separated values
`write_excel_csv()` | CSV that you plan to open in Excel
`write_delim()`     | General delimited files
`write_file()`      | A single string, written as is
`write_lines()`     | A vector of strings, one string per line
`write_tsv()`       | Tab delimited values
`write_rds()`       | A data type used by R to save objects
`write_sas()`       | SAS .sas7bdat files
`write_xpt()`       | SAS transport format, .xpt
`write_sav()`       | SPSS .sav files
`write_stata()`     | Stata .dta files

.center[
and many more...
]

---
# Troubleshooting

.center[![Programmer google joke](data:image/png;base64,#https://s3.amazonaws.com/rails-camp-tutorials/blog/programming+memes/programming-or-googling.jpg)]

---
class:inverse, mline, center, middle

# It's your turn

---
# Exercise 1

- all necessary files can be found on the e-learning page 
  
- read through the [blog post by Malcolm Barret](https://malco.io/2018/11/05/why-should-i-use-the-here-package-when-i-m-already-using-projects/) 
- set up a R-project called *paleoecology_exercises*
  - in this project, create a folder called *R*
  - in this folder *R*, create a new R-script called *1_exercise.R*
  - in the project, create a folder called *data*
  - download the data file *example_dataset.csv* from e-learning
  - place *example_dataset.csv* in the *data* folder
  - use the *1_exercise.R* script, the **here** package, and the **readr** package to load *example_dataset.csv* into R
  - in the project, create a folder called *output*
  - save the data in this *output* folder as *new_dataset.csv*  
   
- celebrate

---
class:inverse, mline, center, middle
# The *dplyr* package

---
# The main verbs of *dplyr*

## `select()`

## `filter()`

## `mutate()`

## `arrange()`

## `summarize()`

## `group_by()`

---
# The main verbs of *dplyr*

## <code>select()</code> = Subset columns (variables)

## `filter()`

## `mutate()`

## `arrange()`

## `summarize()`

## `group_by()`

---
# dplyr

## `select()`

```r
select(<DATA>, <VARIABLES>)
```

---
# dplyr

## `select()`

```r
select(<DATA>, <VARIABLES>)
```

```r
carnivores
```

---
# dplyr

## `select()`

```r
select(carnivores, identified_rank, accepted_name, min_ma, max_ma)
```

```
## # A tibble: 12,168 × 4
## identified_rank accepted_name min_ma max_ma
## <chr> <chr> <dbl> <dbl>
## 1 species Cynodictis lacustris 33.9 37.2
## 2 species Enaliarctos mealsi 23.0 28.1
## 3 species Pinnarctidion bishopi 23.0 28.1
## 4 species Indarctos atticus 7.25 11.6
## 5 genus Protursus 7.25 11.6
## 6 subfamily Ursinae 7.25 11.6
## 7 species Proputorius 7.25 11.6
## 8 species Sivaonyx bathygnathus 7.25 11.6
## 9 genus Lutra 7.25 11.6
## 10 species Ictitherium 7.25 11.6
## # … with 12,158 more rows
```

---
# dplyr

## `select()`

```r
select(carnivores, occurrence_no, record_type, reid_no, flags)

select(carnivores, occurrence_no:flags)

select(carnivores, 1:4)

select(carnivores, starts_with("c"))

?select_helpers
```

---
# dplyr

## `select()`

## <code>filter()</code> = Subset rows by value

## `mutate()`

## `arrange()`

## `summarize()`

## `group_by()`

---
# dplyr

## `filter()`

```r
filter(<DATA>, <PREDICATES>)
```

### Predicates: `TRUE/FALSE` statements

### Comparisons: `>`, `>=`, `<`, `<=`, `!=` (not equal), and `==` (equal).

### Operators: `&` is "and", `|` is "or", and `!` is "not"

### `%in%`

---
# dplyr

## `filter()`

```r
filter(carnivores, accepted_rank == "species", max_ma > 7)
```

```
## # A tibble: 3,235 × 118
## occurrence_no record_type reid_no flags collection_no identified_name 
## <dbl> <chr> <dbl> <lgl> <dbl> <chr> 
## 1 117266 occ NA NA 9070 Cynodictis lacustris 
## 2 137493 occ NA NA 11601 n. gen. Enaliarctos n.…
## 3 137495 occ NA NA 11601 Pinnarctidion bishopi 
## 4 138737 occ NA NA 11798 Indarctos sinensis 
## 5 138741 occ NA NA 11798 Sivaonyx bathygnathus 
## 6 147936 occ NA NA 13061 n. gen. Atopotarus n. …
## 7 149438 occ NA NA 13192 Allodesmus kernensis 
## 8 164284 occ NA NA 14768 Ravenictis n. sp. krau…
## 9 165362 occ NA NA 14906 Ictidopappus n. sp. mu…
## 10 165688 occ NA NA 14939 Pristinictis n. sp. co…
## # … with 3,225 more rows, and 112 more variables: identified_rank <chr>,
## # identified_no <dbl>, difference <chr>, accepted_name <chr>,
## # accepted_attr <lgl>, accepted_rank <chr>, accepted_no <dbl>,
## # early_interval <chr>, late_interval <chr>, max_ma <dbl>, min_ma <dbl>,
## # ref_author <chr>, ref_pubyr <dbl>, reference_no <dbl>, phylum <chr>,
## # class <chr>, order <chr>, family <chr>, genus <chr>, plant_organ <lgl>,
## # plant_organ2 <lgl>, abund_value <dbl>, abund_unit <chr>, lng <dbl>, …
```

---
# The main verbs of *dplyr*

## `select()`

## `filter()`

## <code>mutate()</code> = Change or add a variable

## `arrange()`

## `summarize()`

## `group_by()`
---
# dplyr

## `mutate()`

```r
mutate(<DATA>, <NAME> = <FUNCTION>)
```

---
# dplyr

## `mutate()`

```r
mutate(carnivores, age_range = abs(max_ma - min_ma))
```

```
## # A tibble: 12,168 × 119
## occurrence_no record_type reid_no flags collection_no identified_name 
## <dbl> <chr> <dbl> <lgl> <dbl> <chr> 
## 1 117266 occ NA NA 9070 Cynodictis lacustris 
## 2 137493 occ NA NA 11601 n. gen. Enaliarctos n.…
## 3 137495 occ NA NA 11601 Pinnarctidion bishopi 
## 4 138737 occ NA NA 11798 Indarctos sinensis 
## 5 138738 occ NA NA 11798 Protursus sp. 
## 6 138739 occ NA NA 11798 Ursinae indet. 
## 7 138740 occ NA NA 11798 Proputorius lufengensis
## 8 138741 occ NA NA 11798 Sivaonyx bathygnathus 
## 9 138742 occ NA NA 11798 Lutra sp. 
## 10 138743 occ NA NA 11798 Ictitherium gaudryi 
## # … with 12,158 more rows, and 113 more variables: identified_rank <chr>,
## # identified_no <dbl>, difference <chr>, accepted_name <chr>,
## # accepted_attr <lgl>, accepted_rank <chr>, accepted_no <dbl>,
## # early_interval <chr>, late_interval <chr>, max_ma <dbl>, min_ma <dbl>,
## # ref_author <chr>, ref_pubyr <dbl>, reference_no <dbl>, phylum <chr>,
## # class <chr>, order <chr>, family <chr>, genus <chr>, plant_organ <lgl>,
## # plant_organ2 <lgl>, abund_value <dbl>, abund_unit <chr>, lng <dbl>, …
```

---
# dplyr

## `transmute()`

```r
transmute(carnivores, 
          age_range = abs(max_ma - min_ma), 
          age_range_sq = age_range^2)
```

```
## # A tibble: 12,168 × 2
## age_range age_range_sq
## <dbl> <dbl>
## 1 3.30 10.9
## 2 5.07 25.7
## 3 5.07 25.7
## 4 4.37 19.1
## 5 4.37 19.1
## 6 4.37 19.1
## 7 4.37 19.1
## 8 4.37 19.1
## 9 4.37 19.1
## 10 4.37 19.1
## # … with 12,158 more rows
```

---
# The main verbs of *dplyr*

## `select()`

## `filter()`

## `mutate()`

## <code>arrange()</code> = Sort the data set

## `summarize()`

## `group_by()`
---
# dplyr

## `arrange()`

```r
arrange(<DATA>, <SORTING VARIABLE>)
```

---
# dplyr

## `arrange()`

```r
arrange(carnivores, max_ma) %>% 
  select(max_ma, everything())
```

```
## # A tibble: 12,168 × 118
## max_ma occurrence_no record_type reid_no flags collection_no identified_name 
## <dbl> <dbl> <chr> <dbl> <lgl> <dbl> <chr> 
## 1 0.0117 154618 occ NA NA 13738 Panthera tigris 
## 2 0.0117 212868 occ NA NA 21686 Felis pardalis 
## 3 0.0117 212869 occ NA NA 21686 Felis yagouarou…
## 4 0.0117 212870 occ NA NA 21686 Conepatus semis…
## 5 0.0117 212871 occ NA NA 21686 Eira barbara 
## 6 0.0117 212872 occ NA NA 21686 Galictis vittata
## 7 0.0117 212873 occ NA NA 21686 Procyon cancriv…
## 8 0.0117 212918 occ NA NA 21686 Cerdocyon thous 
## 9 0.0117 212932 occ NA NA 21687 Speothos venati…
## 10 0.0117 212933 occ NA NA 21687 Eira barbara 
## # … with 12,158 more rows, and 111 more variables: identified_rank <chr>,
## # identified_no <dbl>, difference <chr>, accepted_name <chr>,
## # accepted_attr <lgl>, accepted_rank <chr>, accepted_no <dbl>,
## # early_interval <chr>, late_interval <chr>, min_ma <dbl>, ref_author <chr>,
## # ref_pubyr <dbl>, reference_no <dbl>, phylum <chr>, class <chr>,
## # order <chr>, family <chr>, genus <chr>, plant_organ <lgl>,
## # plant_organ2 <lgl>, abund_value <dbl>, abund_unit <chr>, lng <dbl>, …
```

---
# dplyr

## `arrange()`

```r
arrange(carnivores, max_ma, lng) %>% 
  select(max_ma, lng, everything())
```

```
## # A tibble: 12,168 × 118
## max_ma lng occurrence_no record_type reid_no flags collection_no
## <dbl> <dbl> <dbl> <chr> <dbl> <lgl> <dbl>
## 1 0.0117 -177. 653974 occ NA NA 70586
## 2 0.0117 -177. 653975 occ NA NA 70586
## 3 0.0117 -177. 653976 occ NA NA 70586
## 4 0.0117 -176. 1447238 occ NA NA 201978
## 5 0.0117 -173. 819689 occ NA NA 90098
## 6 0.0117 -173. 819690 occ NA NA 90098
## 7 0.0117 -170. 1310863 occ NA NA 175953
## 8 0.0117 -170. 1310864 occ NA NA 175953
## 9 0.0117 -170. 1310865 occ NA NA 175953
## 10 0.0117 -170. 1310851 occ NA NA 175951
## # … with 12,158 more rows, and 111 more variables: identified_name <chr>,
## # identified_rank <chr>, identified_no <dbl>, difference <chr>,
## # accepted_name <chr>, accepted_attr <lgl>, accepted_rank <chr>,
## # accepted_no <dbl>, early_interval <chr>, late_interval <chr>, min_ma <dbl>,
## # ref_author <chr>, ref_pubyr <dbl>, reference_no <dbl>, phylum <chr>,
## # class <chr>, order <chr>, family <chr>, genus <chr>, plant_organ <lgl>,
## # plant_organ2 <lgl>, abund_value <dbl>, abund_unit <chr>, lat <dbl>, …
```

---
# dplyr

## `desc()`

```r
arrange(carnivores, max_ma, desc(lng)) %>% 
  select(max_ma, lng, everything())
```

```
## # A tibble: 12,168 × 118
## max_ma lng occurrence_no record_type reid_no flags collection_no
## <dbl> <dbl> <dbl> <chr> <dbl> <lgl> <dbl>
## 1 0.0117 180. 1429298 occ NA NA 198860
## 2 0.0117 180. 1268080 occ NA NA 168608
## 3 0.0117 178. 1447237 occ NA NA 201977
## 4 0.0117 177. 653978 occ NA NA 70585
## 5 0.0117 177. 805370 occ NA NA 87900
## 6 0.0117 176. 1318554 occ NA NA 177178
## 7 0.0117 176. 1429299 occ NA NA 198861
## 8 0.0117 176. 1447239 occ NA NA 201979
## 9 0.0117 175. 1268186 occ NA NA 168679
## 10 0.0117 175. 1447240 occ NA NA 201980
## # … with 12,158 more rows, and 111 more variables: identified_name <chr>,
## # identified_rank <chr>, identified_no <dbl>, difference <chr>,
## # accepted_name <chr>, accepted_attr <lgl>, accepted_rank <chr>,
## # accepted_no <dbl>, early_interval <chr>, late_interval <chr>, min_ma <dbl>,
## # ref_author <chr>, ref_pubyr <dbl>, reference_no <dbl>, phylum <chr>,
## # class <chr>, order <chr>, family <chr>, genus <chr>, plant_organ <lgl>,
## # plant_organ2 <lgl>, abund_value <dbl>, abund_unit <chr>, lat <dbl>, …
```

---
class:inverse, mline, center, middle
# The pipe
 
## Passes the result on one function to another function

---
# The Pipe

```r
carnivores1 <- arrange(carnivores, max_ma)
carnivores2 <- filter(carnivores, max_ma > 7)
carnivores3 <- mutate(carnivores2, 
 age_range = abs(max_ma - min_ma))

carnivores3
```

--
<html>
 <div style='float:left'></div>
 <hr color='#EB811B' size=1px width=720px>
</html>

```r
mutate(
  filter(
    arrange(carnivores, max_ma), 
    max_ma > 7
    ),
  age_range = abs(max_ma - min_ma)
  )
```

--
<html>
 <div style='float:left'></div>
 <hr color='#EB811B' size=1px width=720px>
</html>

```r
arrange(carnivores, max_ma) %>% 
  filter(max_ma > 7) %>% 
  mutate(age_range = abs(max_ma - min_ma))
```

---
# The Pipe

## Insert with **`ctrl/cmd + shift + m`**

---
# The main verbs of *dplyr*

## `select()`

## `filter()`

## `mutate()`

## `arrange()`

## <code>summarize()</code> = Summarize the data

## <code>group_by()</code> = Group the data
---
# dplyr

## `summarize()`

```r
summarize(<DATA>, <NAME> = <FUNCTION>)
```

---
# dplyr

## `summarize()`

```r
summarize(carnivores, mean_fad = mean(max_ma))
```

```
## # A tibble: 1 × 1
## mean_fad
## <dbl>
## 1 10.8
```

--
<html>
 <div style='float:left'></div>
 <hr color='#EB811B' size=1px width=720px>
</html>

```r
summarize(carnivores, 
          mean_fad = mean(max_ma), 
          sd_fad = sd(max_ma))
```

```
## # A tibble: 1 × 2
## mean_fad sd_fad
## <dbl> <dbl>
## 1 10.8 12.7
```

---
# dplyr

## `group_by()`

```r
group_by(<DATA>, <VARIABLE>)
```

---
# dplyr

## `group_by()`

```r
carnivores %>% 
  group_by(accepted_rank)
```

```
## # A tibble: 12,168 × 118
## # Groups: accepted_rank [12]
## occurrence_no record_type reid_no flags collection_no identified_name 
## <dbl> <chr> <dbl> <lgl> <dbl> <chr> 
## 1 117266 occ NA NA 9070 Cynodictis lacustris 
## 2 137493 occ NA NA 11601 n. gen. Enaliarctos n.…
## 3 137495 occ NA NA 11601 Pinnarctidion bishopi 
## 4 138737 occ NA NA 11798 Indarctos sinensis 
## 5 138738 occ NA NA 11798 Protursus sp. 
## 6 138739 occ NA NA 11798 Ursinae indet. 
## 7 138740 occ NA NA 11798 Proputorius lufengensis
## 8 138741 occ NA NA 11798 Sivaonyx bathygnathus 
## 9 138742 occ NA NA 11798 Lutra sp. 
## 10 138743 occ NA NA 11798 Ictitherium gaudryi 
## # … with 12,158 more rows, and 112 more variables: identified_rank <chr>,
## # identified_no <dbl>, difference <chr>, accepted_name <chr>,
## # accepted_attr <lgl>, accepted_rank <chr>, accepted_no <dbl>,
## # early_interval <chr>, late_interval <chr>, max_ma <dbl>, min_ma <dbl>,
## # ref_author <chr>, ref_pubyr <dbl>, reference_no <dbl>, phylum <chr>,
## # class <chr>, order <chr>, family <chr>, genus <chr>, plant_organ <lgl>,
## # plant_organ2 <lgl>, abund_value <dbl>, abund_unit <chr>, lng <dbl>, …
```

---
# dplyr

## `group_by()`

```r
carnivores %>% 
  group_by(accepted_rank) %>% 
  summarise(n = n(),
          mean_fad = mean(max_ma))
```

```
## # A tibble: 12 × 3
## accepted_rank n mean_fad
## <chr> <int> <dbl>
## 1 family 913 13.4 
## 2 genus 3060 10.4 
## 3 infraorder 7 20.5 
## 4 order 172 20.8 
## 5 species 7637 10.4 
## 6 subfamily 277 13.1 
## 7 subgenus 5 2.28 
## 8 suborder 8 34.5 
## 9 subspecies 27 0.467
## 10 superfamily 8 23.0 
## 11 tribe 26 7.87 
## 12 unranked clade 28 15.0
```

---
# dplyr

## `group_by()`

```r
carnivores %>% 
  group_by(accepted_rank) %>% 
  mutate(n = n(),
         mean_fad = mean(max_ma)) %>% 
  select(n, mean_fad)
```

```
## Adding missing grouping variables: `accepted_rank`
```

```
## # A tibble: 12,168 × 3
## # Groups: accepted_rank [12]
## accepted_rank n mean_fad
## <chr> <int> <dbl>
## 1 species 7637 10.4
## 2 species 7637 10.4
## 3 species 7637 10.4
## 4 species 7637 10.4
## 5 genus 3060 10.4
## 6 subfamily 277 13.1
## 7 genus 3060 10.4
## 8 species 7637 10.4
## 9 genus 3060 10.4
## 10 genus 3060 10.4
## # … with 12,158 more rows
```

---
class: inverse, mline, middle, center
# Joins

---
# dplyr

## Joining data

### Use `left_join()`, `right_join()`, `full_join()`, or `inner_join()` to join datasets
### Use `semi_join()` or `anti_join()` to filter datasets against each other

---
# Joins

.center[
![](data:image/png;base64,#https://raw.githubusercontent.com/gadenbuie/tidyexplain/master/images/left-join.gif)
]

---
# Joins

.center[
![](data:image/png;base64,#https://raw.githubusercontent.com/gadenbuie/tidyexplain/master/images/right-join.gif)
]

---
# Joins

.center[
![](data:image/png;base64,#https://raw.githubusercontent.com/gadenbuie/tidyexplain/master/images/full-join.gif)
]

---
# Joins

.center[
![](data:image/png;base64,#https://raw.githubusercontent.com/gadenbuie/tidyexplain/master/images/inner-join.gif)
]

---
# Joins

.center[
![](data:image/png;base64,#https://raw.githubusercontent.com/gadenbuie/tidyexplain/master/images/semi-join.gif)
]

---
# Joins

.center[
![](data:image/png;base64,#https://raw.githubusercontent.com/gadenbuie/tidyexplain/master/images/anti-join.gif)
]

---
# Reading list

#### [Here package](https://github.com/jennybc/here_here), intro to the `here` package.
#### [Happy git with R](https://happygitwithr.com/), how to use version control with Git/ GitHub as an R user.
#### [R for Data Science](https://r4ds.had.co.nz/index.html), best intro to the tidyverse.
#### [Project-oriented workflow](https://www.tidyverse.org/blog/2017/12/workflow-vs-script/), good working habits by Jenny Bryan.
#### [Modern Dive](https://moderndive.com/foreword.html), statistical inference via the tidyverse.
#### [Cheatsheets](https://www.rstudio.com/resources/cheatsheets/), a compilation of cheatsheets for various packages.

---
class:inverse, mline, center, middle

# It's your turn  
  
---
# Exercise 2

- read the [Introduction to ggplot2 (Part 1)](https://gregor-mathes.netlify.app/2020/06/29/introduction-to-ggplot2-part-1/)

- follow along with the exercises at `exercise_ggplot.R`

.center[<img src="data:image/png;base64,#https://ak2.picdn.net/shutterstock/videos/15323182/thumb/8.jpg" alt="Allison Horsts visualisation of the here function" width="650"/>
]
 
---
# Exercise 3

- this is the final exercise for today

- perform exploratory data analysis on the *carnivores.csv* data set
  - use R-projects and the **here** package to structure this exercise
  - use the **dplyr** functions to get insights from the *carnivores.csv* dataset
  - visualise your insights via the **ggplot** package
  - upload the final visualisation to the e-learning exercise 3